Electromagnetic relays



May 3, 1966 N. D. SUMMERS 3,249,822

ELECTROMAGNETIC RELAYS Filed March 14, 1963 In "1-, For; Var-nan United States Patent- 3,249,822 ELECTROMAGNETIC RELAYS Norman Derek Summers, Fareham, England, a'ssignor to The Plessey Company Limited, Ilford, England, a British company Filed Mar. 14, 1963, Ser. No. 267,380 Claims priority, application Great Britain, Mar. 15, 1962,

7 Claims. (Cl. 317-165) This invention relates to electromagnetic .relays.

In accordance with a first aspect of the invention the magnetic circuit of an electromagnetic relay includestwo substantially L-shaped members which engage with the frame or like element of the relay with corresponding arms of the members lying side by side to form a core for the coil of the relay and the remaining arms of the members being located one at each end of the coil and extending in the same direction to provide pole pieces with a relay armature.

Preferably the said other arms of the members are provided with means for lockably engaging with the frame so as to effectively lock the members to the frame in a predetermined position. Conveniently the free end of each said other arm is provided with a wedging surface which can loclewith a resilient catch provided on the frame.

Preferably the co-operation between the wedging surface and the catch serves positionally to locate the membet with respect to the frame, there being additional locating means in the form of a slot at each end of the frame which is engaged by the associated other arm.

In accordance with a further aspect of the invention the coil carrying bobbin or former of the relay is connected to the frame or like element of the relay by two substantially L-shaped members which form a core for the coil of the relay and which also form pole pieces to coact with a relay armature.

The invention will be further described With reference to the accompanying drawings which show an example of an electromagnetic relay according to the invention.

FIGURE 1 is a side and FIGURE 2 is a section along the line II--II on FIG- URE 1 looking in the direction shown.

FIGURE 3 shows the frame of the relay looking from one end. The position of a pole piece when inserted from this end is shown as a chain-dotted line.

view of the electromagnetic relay,

FIGURE 4 is a section along the line IV--IV on FIG- URE 3 showing the position of one pole piece in the frame of the relay.

The relay has a main frame formed from a single piece of sheet metal such as brass, the frame having a rectangular body part 1, two support pieces 2 for a' coil bobbin 3, the support pieces extending perpendicularly from one pair of opposite edges of the body part and two leg units 4, extending perpendicularly from the other pair of opposite edges on the opposite side of the body part 1. Each support piece 2 is constituted by a flat plate against which the end wall of the coil bobbin 3 abuts. A vertical slot 5 is formed in each of the support pieces 2. One end of the slot 5 terminates at a rectangular hole 6, one side of the hole 6 being defined by the continuation of one side of the slot 5 so that the hole 6 is offset with respect to the slot 5. The off-setting of the hole 6 in one support piece is opposite to that in the other support piece. Each hole 6 is located substantially in the center of its support piece 2 and is of the same dimensions as the bore of the bobbin 3. The other end of each slot 5 intersects the transition zone between thesupport piece 2 and the body part 1. The body part 1 is so cut in the vicinity of the said other ends of the slots 5 as toprovide a resilient ice core of the relay. This corev is constituted by one arm of each of twoL-shaped elements 8. One arm of each element 8 enters into the hole in one support piece 2 with the other arm thereof engaged in the slot 5 ofthe support piece 2, passes through the bore of the bobbin 3 to'iritersect and project outwardly from the other support piece, with the projecting end of, the one arm engaging the oifset part of the hole 6. One of these L-shaped elements 8 in position in a support piece 2 is shown as a chain-dotted line in FIGURE 3. Further detail is given in FIGURE 4. With this arrangement, after fitting the bobbin 3 between support pieces 2, the core elements are entered into the holes 6 from the opposite ends of the bobbin 3. The two long arms of the elements 8 lie side-by-side and substantially fill the holes 6 and the bore a of the bobbin 3. The other arms of the L-shaped elements engage the slots 5.

An inclined wedging surface 7a is formed on each one of the other arms of the L-shaped elements, thewedging surfaces being complementary to the inclined surface of the resilient tongues 7. Thesewedging surfaces 7a mutually interact to lock the core elements 8 in position after they have been fitted to the frame. Preferably the locking is reinforced by a soldering operation, which provides an additional connection between the frame and the core elements 8.

The other arms of the L-shaped elements act as pole faces which co-operate with an armature 9 of the relay.

The armature 9 is pivotally mounted on a pivot pin 10 provided on the body part 1 of the frame. The pivot pin 10 is located at the intersection of the diagonals of the body part, and extends perpendicular to the body part between the leg units '4. The pole faces are arranged in an off-set relationship with respect to the pivotal axis of the armature 9.

The armature 9 'is arranged to pivot transversely of the pole pieces of the core elements 8.

The leg units 4 of the frame are connected to a rectangular base plate 11 which carries a number of spring contacts 12 mounted on pins 13 secured to the base plate with glass-to-metal seals. The spring contacts 12 are arranged as two sets of change-over contacts. Each set comprises two V-shaped resilient contacts each having one end secured to a pin 13 and so arranged that the two springs combine to form an M configuration. A flexible movable contact 12a is fixed by one end thereof to a further pin. The free end of one movable contact 12a co-acts with one end of the armature 9 to one side of the pivot axis, and the other movable contact co-acts with the other end of the armature to the other side of the armature.

The armature 9 swings clear of the contacts and is provided with an insulated abutment pin 14 at each end which pushes the movable contacts 12a andeffects the change over switching. A spring (not shown) returns the armature to a restposition when a magnetic force causing movement of the armature and actuation of the relay is removed. The foregoing description of a particular embodiment of the invention is given as an example only. A number of variations could be made which would still fall within the scope of the invention. For example, the core elements 8 could be fixed to the relay frame by means other than locking and soldering, such as welding or rivetting.

What we claim is: V

1. An electromagnetic relay including a coil, a relay armature, a frame and two substantially L-shaped memmembers lying side-by-side to form a core for the coil r of the relay and the remaining arms of the members being located one at each end of the coil, means supporting said remaining arms laterally in slots in the frame and said remaining arms extending in the same direction to provide pole pieces coacting with the relay armature, the armature being movable in a plane perpendicular to that in which the pole pieces lie.

2. An electromagnetic relay as claimed in claim 1 in which the said remaining arms of the members are provided with means for lockably engaging with the frame so as effectively to lock the members to the frame in a predetermined position.

3. An electromagnetic relay as claimed in claim 2 in which a free end of each of said remaining arms is provided with a wedging surface which can lock with a resilient catch provided on the frame.

4. An electromagnetic relay as claimed in claim 3 in which co-operation between the wedging surface and the catch serves positionally to locate the arm with respect to the frame.

5. An electromagnetic relay comprising a relay frame which supports a relay coil, an armature pivotally mounted within the frame, two substantially L-shaped members which engage with the frame with corresponding arms of the members lying side-by-side to form a core for the coil of the relay and the remaining arms of the members being located one at each end of the relay coil and extending in the same direction, locking means support ing each remaining arm in a slot in the relay frame and the end of, each remaining arm actingas a pole piece to coact with the relay armature, said locking means being provided between the remaining arms and frame effective to hold the arms to the frame in a predetermined position.

6. A relay according to claim 5, wherein the locking means between the remaining arms and frame includes a wedging surface on each remaining arm which co-operates with resilient catch means carried on the relay frame.

7. A relay according to claim 5, including a contact assembly supported on a base upon which the relay frame is mounted, the contact assembly including at least one resilient contact arm which may be engaged and moved by means of abutment pins carried on the relay armature.

References Cited by the Eiraminer UNITED STATES PATENTS Welch et a1. 317 197 X BERNARD A. GILHEANY, Primary Examiner.

JOHN F. BURNS, Examiner.

LARAMIE E. ASKIN, G. HARRIS, 1a.,

Assistant Examiners. 

1. AN ELECTROMAGNETIC RELAY INCLUDING A COIL, A RELAY ARMATURE, A FRAME AND TWO SUBSTANTIALLY L-SHAPED MEMBERS WHICH ENGAGE THE FRAME, CORRESPONDING ARMS OF THE MEMBERS LYING SIDE-BY-SIDE TO FORM A CORE FOR THE COIL OF THE RELAY AND THE REMAINING ARMS OF THE MEMBERS BEING LOCATED ONE AT EACH END OF THE COIL, MEANS SUPPORTING SAID REMAINING ARMS LATERALLY IN SLOTS IN THE FRAME AND SAID REMAINING ARMS EXTENDING IN THE SAME DIRECTION TO PROVIDE POLE PIECES COACTING WITH THE RELAY ARMATURE, THE ARMATURE BEING MOVABLE IN A PLANE PERPENDICULAR TO THAT IN WHICH THE POLE PIECES LIE. 